POS0778 THE USEFULNESS OF ULTRASOUND-GUIDED CORE NEEDLE BIOPSY OF THE PAROTID GLAND FOR THE DIAGNOSIS OF PRIMARY SJÖGREN’S SYNDROME
Authors: A. Zabotti, I. Giovannini, V. Manfrè, M. Lorenzon, E. Pegolo, C. Dejaco, A. Hocevar, L. Quartuccio, S. De Vita
Journal: Annals of the Rheumatic Diseases (2022)

Background Ultrasound-guided Core Needle Biopsy (US-guided CNB) of the parotid gland has proved to be a novel and safe technique for the diagnosis of lymphoma in Sjögren’s Syndrome (pSS) patients with salivary gland enlargement. 1 The potential role of US-guided CNB for the diagnosis of pSS has been never reported, while only one group uses open surgical parotid biopsy to this end in pSS 2 . Objectives To explore the value of US-guided CNB of the parotid gland as a diagnostic tool for pSS. Methods From September 2019 to June 2021, 22 patients with a clinical diagnosis of pSS underwent US-guided CNB of the parotid gland due to persistent (≥2 months) parotid swelling and suspected glandular lymphoma. In 21/22 (95.4%) patients, the tissue sampling was adequate for the histopathological diagnosis. No persistent complications were reported. For the aim of this study, 2/21 (9.5%) patients were excluded for a different final diagnosis (i.e., IgG4-RD and sarcoidosis), and 13/21 (61.9%) patients for a diagnosis of parotid gland lymphoma. Six out of 21 (28.5%) were finally included for the evaluation of US-guided CNB in the histopathological diagnosis of pSS. The following histopathological features related to pSS were studied: focus score (FS); presence of germinal centres (GCs); presence of lymphoepithelial lesions (LELs); and presence of Myo-/Lympho-epithelial sialadenitis (MESA/LESA). Results All 6 patients already satisfied the ACR/EULAR classification criteria for pSS and were females, with a mean age of 47.6 years (SD ±17.0) and a mean disease duration of 8.3 years (SD ±8.0). In all of them, specific findings of pSS were observed (Table 1). The FS could be calculated in 3/6 cases and was ≥1 in 2/3 cases, while in 3/6 cases it could be not calculated due to the evidence of MESA/LESA. GCs were found in 4/7 cases, while LELs were present in 3/7 cases (Table 1). Table 1. Histopathological features in the parotid gland biopsy. #Patient Focus score LELs GCs MESA/LESA #1 NI Not applicable ✗ ✗ ✓ #2 BM ≥1 ✓ ✓ ✗ #3 CM Not applicable ✓ ✓ ✓ #4 RC &lt;1 0 ✓ ✗ #5 FR Not applicable ✓ ✓ ✓ #6 RV ≥1 ✗ ✗ ✗ Conclusion US-guided CNB of the parotid gland could represent a potential novel tool for the diagnosis of pSS patients. When parotid swelling is present, it may be more convenient than lip biopsy. In addition, CNB can be ultrasound-guided in specific glandular areas showing different sonographic appearances, consistent with different histopathology, leading the way for the role as diagnostic tool for pSS, and not only as improved lymphoma detection tool. The next step is to evaluate US-guided CNB in pSS patients without glandular swelling, and to compare the results with labial biopsy. References [1]Zabotti A, Zandonella Callegher S, Lorenzon M, et al. Ultrasound-guided core needle biopsy compared with open biopsy: a new diagnostic approach to salivary gland enlargement in Sjögren’s syndrome? Rheumatology . Published online September 17, 2020:keaa441. doi:10.1093/rheumatology/keaa441 [2]Spijkervet FKL, Haacke E, Kroese FGM, Bootsma H, Vissink A. Parotid Gland Biopsy, the Alternative Way to Diagnose Sjögren Syndrome. Rheumatic Disease Clinics of North America . 2016;42(3):485-499. doi:10.1016/j.rdc.2016.03.007 Disclosure of Interests Alen Zabotti Speakers bureau: Not relevant for this study, Consultant of: Not relevant for this study, Ivan Giovannini Speakers bureau: Not relevant for this study, Valeria Manfrè: None declared, Michele Lorenzon Speakers bureau: Not relevant for this study, Enrico Pegolo Speakers bureau: Not relevant for this study, Christian Dejaco Speakers bureau: Not relevant for this study, Consultant of: Not relevant for this study, ALOJZIJA HOCEVAR Speakers bureau: Not relevant for this study, Consultant of: Not relevant for this study, Luca Quartuccio Speakers bureau: Not relevant for this study, Consultant of: Not relevant for this study, Salvatore De Vita Speakers bureau: Not relevant for this study, Consultant of: Not relevant for this study